Broken casing coupling means with removable inner guide and permanent overshot



Feb. 26, 1963 J. a. WALVOORD IETAI. 3, 7

BROKEN CASING COUPLING MEANS WITH REMOVABLE INNER GUIDE AND PERMANENTOVERSHOT Filed Sept. 14, 1961 FIG.\. l FIGZ.

1 k 7 7' I 313% L I i I ii 11 I x 3 1 W 2 :k i E 5 I 5 l 1- 7 94 k I I9'44 I97 n H l H4 l 5 1 I34 1 I3 k IS l i I57 I l i l6+ i 1 5 17 I7 I 23l I 23 I a \[l :;l |l I l I I I I I 1| I 27- I I I 274 k 11 L JAMES s.WALVOORD, GEORGE H. HACKE, I y VERGIL GARLINGTON,

ATTORNEY.

\ INVENTORS.

United States Patent fifice 3,079,177 Patented Feb. as, was

BROKEN CASING cohrirNo MEANS wrrrr RE- MOVABLE INNER onion ANDPERMANENT.

ovnusnor James G. Walvoord and Vergil L. Garlington, Grand isle, 'andGeorge H. Hacke, New Orleans, La, assignors, by mesne assignments, toJersey Production Research Company, Tulsa, Okla, a corporation ofDelaware Filed Sept. 14, 1961, Ser. No. 138,184 2 Claims. (Cl. 285-27)This invention relates to apparatus for assembling a pipe string in aborehole, and more particularly to apparatus for facilitating theinterconnection of well pipe string sections where one section ispermanently positioned in the bottom of a borehole.

It is not uncommon for a section of a well pipe string, such as a casingstring, to corrode or be otherwise damaged so that it is necessary tocut the casing below the damaged portion in order to effect a repair. Insuch a circumstance, the operator has the choice or" attempting thereconnection of the pipe string sections or of bypassing the casingstring remaining in the bottom of the well bore by directional drillingtechniques. It is manifest that reconnection of the pipe string sectionsis the most desirable of the above alternatives, and it is also apparentthat such reconnection can be quite difiicult.

In accordance with the teachings of the invention, a tubular extensionmember is provided for the upper pipe string section, having an innerdiameter somewhat greater than the outer diameter of the lower pipestring section, or fish, remaining in the borehole. Grapple means areprovided in the extension member for gripping the lower pipe stringsection when slid thereover. Detachably connected to the tubularextension member Within the bore thereof is a retrievable guide memberextending through the extension member to below the lower end of theextension member so as to enter the bore of the lower pipe stringsection. When the tubular extension member is lowered over the lowerpipe string section, the guide member serves to locate the pipe stringsection and properly position the extension member thereover. After thegrapple is set, the guide member is disconnected and retrieved from theborehole, thus providing a bore through which other pipe strings may belowered or through which produc ion may be initiated.

Objects and features of the invention not apparent from the abovediscussion will become evident upon consideration of the following moredetailed description thereof when taken in connection with theaccompanying drawings, wherein:

FIG. 1 is an elevational view partially in cross section of anembodiment of the invention in position in a bore hole during connectionoperations; and

FIG. 2 is an elevatioual view of the apparatus of FIG. 1 after the wellpipe sections have been interconnected.

With reference now to FIGS. 1 and 2, there is shown a lower casingstring 27 in a borehole 25. It is assumed that the lower casing section27 has become twisted off during a well completion operation and that itis desired to reconnect an upper casing string thereto. A section of anupper casing string 1 is illustrated as being of somewhat greaterdiameter than the diameter of lower casing string 27. A tubularextension member for casing string 1 comprises a casing sub or safetyjoint 5 threadedly connected to the housing of a casing patch tool 11,and a lowermost outer guide member 23. Within the housing of casingpatch tool 11 is positioned grapple or slips 13 connected to an annularcarrier member 15 therefor. The carrier member 15 rests on a shoulder 17at the upper end of outer guide member 23 and includes an annularsealing element 16 for effecting a fluid seal between carrier member 15and the casing patch tool housing. It is manitest that the grapple 13and the carrier member 15 therefor will be securely held within thecasing patch tool housing. A suitable casing patch tool is illustratedand described at page 796 of the Composite Catalog of Oil FieldEquipment and Services, 22d edition (1957).

Left-hand internal threads 7 are provided in the bore of the tubularextension member immediately above the grapple 13. The threads are hereshown as being within the bore of the safety joint 5. The function ofthe threads will become apparent below. The inner diameter of the outerguide member 23 is somewhat greater than the outer diameter of casingsection 27 so that the outer guide member can slide over the casingsection to permit the grapple 13 to grip the casing section 27 after thegrapple is slid thereover.

A retrievable guide member 19, having a threaded upper section 9matching the threads '7, is shown extending from the casing sub 5 tosubstantially below the lowermost end of outer guide mmeber 23.Preferably, the inner guide member 19 is in the form of a truncated coneso as to facilitate stabbing of the guide member into the bore of thecasing section 27. The space between the inner guide member 19 and thegrapple 13 is substantially greater than the thickness of the casingsection 27. A fishing neck 3 is afiixed to the upper end of the innerguide member 19 so that a work string overshot 33 (see FIG. 2) in thelower end of a work string 31 may be slid thereover and affixed thereto.A longitudinal bore 21 extends through the inner guide member 19 andfishing neck 3 so that fluids may pass therethrough into the bore of thecasing string 1 as the casing string is lowered through the borehole.

The apparatus described above is lowered until the lower end of theinner guide member 153 is substantially at the upper end of casingstring 27. The guide member 19 is stabbed into the bore of the casing27, and the string is lowered until the grapple 13 grips the casingstring 27, as shown in FIG. 2. A work string 31 and overshot 33,preferably having slips therein, are lowered in the casing until thefishing neck 3 is engaged and gripped. The inner guide member 15 isrotated counterclockwise, as viewed, until it is released from thesafety joint 5. After the inner guide member 19 and work string havebeen removed from the borehole, a mill is lowered through the casingstring 1 to cut out the internal threads 7 in the safety joint 5. If itis so desired, casing 1 may be dis connected from safety joint 5 and acasing string of smaller diameter may be connected thereto.

The invention is not necessarily to be restricted to the specificstructural details or arrangement of parts herein set forth, as variousmodifications thereof may be efiected without departing from the spiritand scope of the invention.

The objects and features of the invention having been completelydescribed above, what is claimed is:

1. Apparatus for connecting together upper and lower pipe stringsections in a borehole, comprising:

a tubular extension member for said upper pipe string section having aninner diameter greater than the outer diameter of said lower pipe stringsection;

annular grapple means connected in said extension member for grippingsaid lower pipe string section when slid thereover;

a retrievable inner guide member detachably aiiixed to the upper end ofsaid extension member within the bore of said extension member abovesaid grapple means and extending through said extension member andgrapple means to below the lower end of said extension member so as toenter the bore of said lower pipe string section, said guide memberhaving a longitudinal bore therethrough; and

a fishing neck connected on said guide member extending above thethreaded portion thereof to permit disengagement of said guide memberfrom said extension member and retrieval of said extension member fromthe pipe string.

2. Apparatus for connecting together upper and lower pipe stringsections in a borehole, comprising:

a tubular extension member for said upper pipe string section having aninner diameter greater than the outer diameter of said lower pipe stringsection;

grapple means in said extension member for gripping said lower pipestring section when slid thereover;

internal threads in the bore of said tubular extension member above saidgrapple means;

a retrievable, substantially conical inner guide member having athreaded upper portion engaging said internal threads of said tubularextension member, extending below the lower end of said extension memberto enter the bore of said lower pipe string section;

said guide member having a longitudinal bore therethrough and a fishingneck on said guide member extending above the threaded portion thereofto permit disengagement of said guide member from said extension memberby a work string overshot.

References Cited in the tile of this patent UNITED STATES PATENTS1,751,998 Hinderliter Mar. 25, 1930

2. APPARATUS FOR CONNECTING TOGETHER UPPER AND LOWER PIPE STRINGSECTIONS IN A BOREHOLE, COMPRISING: A TUBULAR EXTENSION MEMBER FOR SAIDUPPER PIPE STRING SECTION HAVING AN INNER DIAMETER GREATER THAN THEOUTER DIAMETER OF SAID LOWER PIPE STRING SECTION; GRAPPLE MEANS IN SAIDEXTENSION MEMBER FOR GRIPPING SAID LOWER PIPE STRING SECTION WHEN SLIDTHEREOVER; INTERNAL THREADS IN THE BORE OF SAID TUBULAR EXTENSION MEMBERABOVE SAID GRAPPLE MEANS; A RETRIEVABLE, SUBSTANTIALLY CONICAL INNERGUIDE MEMBER HAVING A THREADED UPPER PORTION ENGAGING SAID IN-